Rhododendron 'Razzberry', which is a natural hybrid collected in 1962 from Allatoona Lake, GA registered by Earl Sommerville documented as containing Rhododendron flammeum and Rhododendron periclymenoides, has been determined to be a diploid using flow cytometry by
Dr. João Loureiro, Dr. Silvia Castro, José Cerca Oliveira, and Mariana Castro
Plant Ecology and Evolution Group,
Centre for Functional Ecology,
Department of Life Sciences,
Faculty of Science and Technology,
University of Coimbra, Portugal.
Summary of Ploidy Levels
Diploid Rhododendron flammeum,
Diploid Rhododendron periclymenoides,
Diploid Rhododendron 'Razzberry'
Source: Planview Nursery
John and Sally Perkins
